Do you know anything about the invention of the bar code(条形码)?

A small food store owner found it was1to keep records of product information. In 1948, He asked the Drexel Institute of Technology to solve this2. Bernard Silver, a graduate student, was 3in it. He and his friend Norman Joseph Woodland4to work on it. 5, they invented their first working system.

The system did work6, but it was very expensive and 7the system didn't work well. If the invention was to become8 in stores, the problems had to be solved. Finally, Woodland solved9.

The patent for the bar code system was 10for by Silver and Woodland in 1949, but the patent was not given until 1952. 11this patent was given, the system was still not popular12 storeowners.

In 1970, a business named Logicon Inc.13the Universal Grocery Products Identification Code(食品工业统一码). Marsh Supermarket in Troy was the first store to14this bar code reading system. It has become very popular ever since, and now it's15in all types of stores all over the world.

Tony's class will be on a visit to the museum next week. He'd like to take some photos and put them upon the school (网站), so he wants to borrow the (照相机) from his father. His father says that they waited for weeks to hear from their pen friends (在国外) when he was at school. But Tony can send and receive photos and (邮件) on the Internet nowadays. Tony thinks the Internet and computer have changed their lives. They even use online (教科书) in their classes. His father says in the past, they (主要地) got information from paper books. Some books were huge ones with thousands of (页). But with the invention of the computer and (电子的) technology, it's easy to get information on the Internet. So they think the Internet is more (有影响力的) than books.

His father (借给)him the camera. Because it is a gift from his mother, his father asks him to promise that he will look after it.

When you think of robots, you might think of something to perform boring tasks, 1engineers today are making robots that can do much more interesting jobs.

Homie Choset at Carnegie Mellon University in Pittsburgh is a roboticist, a person 2 designs, builds or programmes robots. When Choset was a kid, he was interested in anything that 3—cars, trains, animals. Later, in high school, he built mobile robots similar4small cars. Hoping to continue working 5robots, he studied computer science in college. Some robots can move only forward, backward, left and right,  but snakes can wist (绕，卷)in many 6"Snakes are far more interesting than the cars, "Choset said.

After he started working at Carnegie Mellon, Choset and his colleagues there began developing7own snake robots. A typical snake robot is made up of a lot of metal containers linked together, each with a motor and electronic parts 8Choset's team programmed robots to perform the same movements as real snakes. The robots also move in ways that snakes9don't, such as rolling. Choset's snake robots could crawl (爬) 10 the grass, swim in a pond and even climb a flagpole.

"Snake robots go11 we can't, "says Choset. Snake robots could one day search for victims after an earthquake. And Choset's snake robots might be12 for heart surgeries(外科手术)as well. Choset is thinking of sending robots into Egyptian archaeological (考古学的)sites that are too small or13for people to enter. A robot 14a camera could show scientists what is inside.

Even after 15 years of working with his team, ""I still don't get 15 with watching the motion of my robots, "Choset says.

We're now used to wearing masks in public. It's reported that about 300 million masks are used and then thrown away every day in China. Where do these used masks go? You might think that they just go in a dustbin (垃圾箱). But that's just the first stop on them asks' journey.

After the masks are thrown into bins, dust carts empty the bins and take the rubbish to landfills(垃圾场). There the masks will be burned. Burning masks might not seem to be very good for the environment. Won't it cause pollution?

The answer is "no", according to People's Daily. That's because most masks are made of non-woven fabrics , whose main material (材料) is polypropylene, an environmentally-friendly material. It's non-toxic (无毒的)and can break down easily. After burning, it turns into water and carbon dioxide. As long as landfills deal with these emissions (排放物)correctly, burning the masks won't cause pollution.

In fact, burning the masks has some advantages. The process of burning rubbish can create electricity. Burning one ton of rubbish means more than 400kilowatt hours of electricity. It's said that there will be 162, 000 tons of used masks in total in China this year. Burning all of them can create 64 million kilowatt hours of electricity. That is enough to allow an electric car to drive 370 million km.

What's more, the waste from burning masks can be recycled to make bricks or fill roadbeds.

Thomas Alva Edison loved to question(对……有疑问)things. He loved to learn how things worked. He also loved to make things work better. Many people think of him as one of the greatest inventors.

Thomas Alva Edison was born on February 11, 1847. Alva did not do well in school. He always had a lot of questions and liked to explore them. At that time, school was mostly about remembering facts. Alva's mum took him out of school and taught him at home. She taught him to love to read.

Alva sold food and newspapers on trains when he was young. He used the money he earned to buy books and materials for experiments. He set up a lab in1876. Also around this time, Alva lost most of his hearing. He saved a boy from being struck by a runaway train. The child 's father offered to teach Alva how to be a telegraph(电报) operator.

As Alva grew older, he travelled around as a telegraph operator. He continued to be interested in science. Edison wanted to invent things full time.

The telephone was invented in 1876, but it didn't work well. In 1877, Edison and his team invented away to make the telephone work better. Edison also invented a machine that could record words and then play them back.

Edison continued to invent new things. During his life, Edison had l, 093 US patents (专利证书) in his name, as well as many patents in the United Kingdom, France, and Germany. He worked until he was more than eighty years old.

Computers and the Internet  in classrooms now.

We  computers more than books in the future.

My friend a computer me.